The invention relates to a process to produce a workpiece surface using a machining machine with a laser that produces laser beam pulses. The machining machine additionally has a laser head that directs the laser beam pulses of the laser onto the workpiece. A machine drive unit with at least one machine axis drive orients and moves, through the respective associated machine axis drive, the workpiece and the laser head relative to one another in at least one translational and/or rotational degree of freedom.
Such a machining process is disclosed by DE 10 2010 011 508 A1, for example. This process produces a rotary tool during the machining of the workpiece. The laser beam pulses of the laser are directed onto a pulse area using a deflection device or a laser scanner of the laser head, and, within this pulse area, they are directed onto points of incidence along a specified pulse path. The pulse area is moved along the surface of the workpiece by the machine drive unit. This relative motion between the pulse area and the cylindrical workpiece is parallel to the machined surface of the workpiece, for example in the axial direction, and material is removed layer by layer. This allows the depth of the material removal to be increased layer by layer, to produce a groove, for example. The pulse area moves multiple times from the beginning of the groove to its end, and back to the beginning of the groove, this movement being repeated until the groove is finished.
A similar process is also disclosed in DE 10 2010 011 508 A1. This process also produces a contour on a workpiece, in particular a cutting edge or a flank, by defining a pulse area with multiple points of incidence for laser beam pulses, this pulse area then being moved through the machine axis drive along the workpiece surface, to remove material layer by layer, and finally to expose a surface on the workpiece.
DE 10 2011 116 974 A1 discloses a process for laser cutting of a workpiece or of a tool which has cutting tools applied to it that are rotationally moved about the tool's longitudinal axis when it is being operated. The cutting tools are supposed to have a chamfer. To accomplish this, a laser beam is oriented at right angles to the longitudinal axis. The workpiece is then moved by a rotation so that the cutting tools are rotated on a circular path, to which the laser beam runs tangentially. The multiple cutting tools applied to the workpiece are supposed to be rotated one after the other, so to speak, into the focal point of the laser, causing material to be removed on the cutting tools one after the other. This material removal can have a movement in the axial direction superimposed on it, so that the chamfer can be produced along the axial edge of the cutting tool.
EP 0 870 578 A1 describes an abrasive tool and a process to produce it. This tool contains abrasive grains, for example of diamond or other abrasive, hard materials. A laser is used to produce holes or grooves in the flat outside of these abrasive grains 11, to form sharp corners and edges.
Producing tool surfaces, for example groove inner surfaces, on a rod-shaped workpiece using a pulsed laser is difficult. Using the above-described process, in which a pulse area is moved over the workpiece surface transverse to the emission direction of the laser beam pulses, it is possible to achieve high removal rates. However, in some cases the workpiece surfaces that are produced, which have laser beam pulses impinge on them, have insufficiently low roughness. Although other known processes have satisfactory surface quality, they achieve only low removal rates, so that these processes are only suitable for removing small volumes of material.
Therefore, processes are sought which first of all allow the production of a workpiece surface, for example a groove inner surface, that has a very low roughness on all surface sections, which do so without finishing of the workpiece surface produced when the material is removed, and also allow high material removal rates.